The objectives of the study are to compare the response rate and time to progression of single-agent Adriamycin, single-agent Taxol, and the combination of Adriamycin and Taxol in patients with previously untreated metastatic breast cancer. Additionally, the study will compare the toxicity of Adriamycin and Taxol in combination to determine whether Taxol and Adriamycin exhibit crossover resistance to each other. The quality of life of patients who have received as first-line therapy for metastatic breast cancer will be compared to the quality of life of patients who have received Taxol or Adriamycin as second-line therapy. Lastly the study will evaluate the relation of steady state Taxol levels to therapeutic response and toxicity.